U.S. Pat. No. 3,800,677 granted Apr. 2, 1974 to Charles W. Jones and Dwight L. Stetler discloses apparatus for forming, and U.S. Pat. No. 3,775,943 granted Dec. 4, 1973 to Charles W. Jones discloses apparatus for filling and sealing straw-bearing cartons. The apparatus and method of the present invention, to be described hereinafter, are intended to form, fill, and seal similar cartons. The carton formed by the apparatus and method of the present invention is the type disclosed in U.S. Pat. No. 3,749,300 granted July 31, 1973 to Charles W. Jones as well as the improvements thereon as shown in U.S. Pat. No. 4,011,984 granted to Matovich, Jr. issued Mar. 15, 1977, and U.S. patent application, Ser. No. 911,990, filed June 2, 1978 by Josef J. Buschor, and now abandoned, which application is a continuation-in-part of U.S. patent application, Ser. No. 822,500, filed Aug. 8, 1977.
Basically, the carton disclosed in each of these patents and applications comprises a rectangular cross-section container formed from a one-piece, substantially T-shaped blank of polyethylene coated paperboard. The carton may be provided on one of its sides with an access flap to the inside of which is attached a straw element. The liquid contents of the carton may be consumed by lifting the access flap, thereby rotating the straw to expose one end of the straw element from which the contents of the carton may be drawn into the mouth, and lowering the other end of the straw into a corner of the carton.
In the formation of the carton by the apparatus shown in U.S. Pat. No. 3,800,667, both ends of the carton blank are sealed prior to the filling operation. As disclosed in U.S. Pat. No. 3,775,943, the access flap is lifted and the carton filled therethrough, after which the aperture is sealed by the application of a length of tape. U.S. Pat. No. 4,037,370 discloses apparatus for closing and sealing the carton wherein the carton is filled from the top of the container and subsequently a cover member is pressed flat down upon the open end of the filled carton and sealed thereto by the melting and cooling of the polyethylene coating on the top of the open-ended carton. Although these prior art methods and apparatus for forming the carton have proven useful in their limited application, they have presented certain cost, space, and production and reliability problems.
In particular, the prior art apparatus for forming the carton has required an extremely large and elongated structure wherein an individual carton blank was formed, filled, and sealed by progression through a series of work stations oriented in an extended production line manner. This large and elongated structure required a considerable amount of space within a plant facility to be devoted to the apparatus, which detracted from the overall efficiency of the device and permitted the installation of the apparatus in only large production facilities.
Further, the prior art apparatus typically facilitated the formation, filling, and sealing of the carton in a serial manner along the production line (i.e., one carton being formed at a time) which, due to the time required for filling and sealing of the carton, limited production output and necessarily increased production costs.
Additionally, due to the elongate nature of the apparatus for forming the carton and the intricate mechanical mechanisms and extended transport mechanisms utilized therein, one or more skilled technicians were required to constantly monitor and fine tune the apparatus during operation. Further, the prior art apparatus was incapable of providing a simple and convenient method of accommodating differing sized containers for different production runs. As such, the versatility of the prior art apparatus was severely limited.